1. Field of the Invention
The invention relates in general to a method of forming an alignment film, and more particularly to a method of forming an alignment film by way of exposure.
2. Description of the Related Art
Conventionally, the formation of alignment film includes a dispensing process, a baking process, an aligning process and a cleaning process. Firstly, polyimide (PI) is dispensed on two substrates respectively and used as a material of the alignment film. Then, the substrates are baked in a firing furnace for thermosetting the alignment film. Then, an alignment apparatus (such as rollers) is used to form recesses in a pre-determined direction on the thermoset alignment film by way of rubbing. Lastly, the two substrates are cleaned with a cleaning apparatus. Thus, recesses and angle are formed on the alignment film in a particular direction, so that liquid crystal molecules can be arranged in order. After the two substrates both form an alignment film, subsequent procedures of panel fabrication are performed for aligning and bonding the two substrates and interposing liquid crystal molecules to the recesses.
According to the generally known technique, the alignment film is formed in a contact manner, that is, recesses are formed by rubbing the alignment film. Since the powders or scraps left after the rubbing process need to be cleaned up with a cleaning apparatus, additional manufacturing procedures and costs are required. In addition, the rubbing process may generate unexpected recesses or scratches and reduce the conformity rate, and the static electricity generated during the rubbing process may damage the circuits on the substrates. Besides, the alignment apparatus boosts the production cost.